Final answer:
The false statement about MRI scanning machines is that the magnet takes 20-30 minutes to warm up. MRI scanners utilize a superconducting magnet that, once cooled to operational temperature, is always on. The functioning of MRI involves creating magnetic fields, emitting and receiving RF pulses, and imaging detailed soft tissues. The correct option is 2).
Step-by-step explanation:
Magnetic Resonance Imaging (MRI) scanners are complex medical devices used to visualize detailed internal structures. The magnet strength of an MRI scanner is generally between 1 and 2 Tesla (T), although some newer models may operate at 3T or higher. The superconducting magnet is a crucial component of an MRI system, creating a magnetic field over a large volume and allowing for the imaging of protons, primarily hydrogen nuclei, in the body. The MRI machine emits radio-frequency (RF) pulses which are absorbed and reemitted by protons in the body, creating signals that can be transformed into images. These images can show soft tissue details, including the function of organs, the condition of tissues, and the shapes of various structures.
The process of warming up the MRI machine is related to the superconducting magnet reaching its operational temperature, which is typically achieved by the use of liquid helium rather than a simple warm-up phase as suggested. Thus, the incorrect statement about MRI scanners is that the magnet takes 20-30 minutes to warm up, as it instead requires a cooling period to reach superconductivity, and once operational, the magnet is always on unless it is specifically turned off for some reason (a process known as quenching).
The energy released from the reemitted RF pulses provides critical information for imaging soft tissues and is crucial for medical diagnoses, such as identifying tumors, inflammatory conditions, and other abnormalities. Additionally, MRI scans are vital in viewing both normal and abnormal tissues, greatly aiding medical professionals in accurate diagnostics. In the final part, it is evident that the incorrect option for MRI scanning machines is that the magnet takes 20-30 minutes to warm up.